906 research outputs found

    Quantum Mechanical Experiments using Optical Techniques in Space

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    The focus of this work is discussing the realization of space based experiments testing quantum mechanics, specifically quantum optics. The main experimental work is the practical realization of the earthbound part of a possible interferometric experiment that can be realized with a delayed-choice operational mode. The full Earth-satellite realization of this experimental scheme could set a new record on the distance to which delayed-choice schemes have been experimentally realized. General relativistic effects on Earth-satellite experiments is also discussed, in the case of two different setups. One of those is essentially the ground-space implementation of the interferometer realized in the laboratory, while the other represents a different possibility that could in principle measure gravitational redshift to single photons to greater extent. Which-path behavior and interference were observed to a very good degree on the interferometer realized in the lab. Specifically, the assessment of interference visibility, which was done after careful alignement of the setup, yields a value of approximately 95%, and a comparable value of approx 93% was obtained with an alternative setup which was also experimentally realized in the laboratory. As far as theoretical computations are concerned, a good formalism to deal with space-based interferometric measurements was pointed out, which allows to take into account both special relativistic contributes and general relativistic corrections to the amplitude describing the photons involved with this kind of experiments. Two different setups, which are candidates for the measurement of single photon gravitational redshift, were analyzed with this formalism. The setup with one interferometer on the ground and the other on the satellite, in principle, constitutes a good way to observe this effect by means of a phase measurement, to the first order in the gravitational potentials.ope

    Sweeten our crops. Sustain a high diversity of beneficials through "sweet food" from plants

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    Sweeten our crops. Sustain a high diversity of beneficials through "sweet food" from plants. A sweet tooth overhangs the terrestrial ecosystems, it is nursed by plants constantly producing pollen and nectar and indirectly honeydew and honey. Truly the "green" Earth is "a land flowing with milk and honey" for myriads of species: from lizards to bees, from birds to flies, from man to ants, through marsupials, beetles, bats and so on. This sweet plant-provided food is the powerful basis of pollination and of many other multi-trophic interactions

    The Larvae of European Ascalaphidae (Neuroptera)

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    The larvae of all the European genera of Ascalaphidae are compared for the first time, highlighting the differential characters for identification purposes. The larva of the genus Ascalaphus is described for the first time while those of Puer, Bubopsis and Deleproctophylla are deeply revised. Actually, the larvae of Ascalaphus festivus (Rambur), Puer maculatus (Olivier), Bubopsis agrionoides (Rambur), Deleproctophylla australis (Rambur), Libelloides latinus (Lefebvre), Libelloides corsicus (Rambur) and Libelloides siculus (Angelini) are described or accurately depicted for the first time. The known larvae of the genus Libelloides are reviewed

    La Protezione del verde urbano

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    Viene riportata una rassegna dei principali insetti fitofagi che danneggiano le essenze vegetali più diffusamente impiegate in Sardegna nel verde urbano (pini, cipressi, leccio, olmi, Ficus, platano, robinia, tiglio, palme, pittosporo, evonimo ed oleandro) e compiuto un esame dei possibili interventi di lotta compatibili con l’ambiente cittadino
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